Reduced adherence to inhaled corticosteroids (ICS) during tezepelumab treatment does not appear to compromise clinical outcomes in severe asthma over 12 months, according to new data, suggesting that the biologic’s broad anti-inflammatory activity may enable some patients to safely reduce their steroid use.
A real-world cohort study led by Guy’s Severe Asthma Centre in London examined whether adult patients prescribed tezepelumab for severe asthma could reduce their reliance on high-dose ICS without loss of disease control.
Eligibility for tezepelumab followed National Institute for Health and Care Excellence criteria, meaning patients had to have experienced three or more asthma exacerbations requiring oral corticosteroids in the previous year and/or be on maintenance oral corticosteroids, with biochemical confirmation of ongoing steroid use.
All patients were required to demonstrate appropriate adherence to high-dose ICS before initiation, and a regional multidisciplinary severe asthma team approved each case.
The cohort included both biologic-naive individuals and those switched from another biologic because of inadequate response, ensuring that all participants met the recognised definitions of severe uncontrolled asthma before starting tezepelumab.
ICS adherence and tezepelumab
The retrospective analysis assessed 152 adults who completed one year of treatment, having initiated therapy between January 2023 and February 2024.
ICS adherence was measured using the medicines possession ratio (MPR) and categorised as good (≥0.75), suboptimal (0.51–0.74) or poor (<0.5) across the treatment year. After 12 months, adherence was good in 69.1% of patients, suboptimal in 12.5% and poor in 18.4%.
Median adherence declined from 1.0 at baseline to 0.83 at one year, indicating that many patients reduced their use of ICS/long-acting beta-2 agonists (LABAs) while on tezepelumab.
Despite this fall in adherence, clinical outcomes remained largely unchanged across all groups. Improvements in annual exacerbation rate, Asthma Control Questionnaire score, lung function and reductions in maintenance oral corticosteroids were comparable across adherence categories.
Similarly, rates of clinical remission, biological remission and complete remission showed no significant variation by adherence level.
Anti-T2 effects may support steroid reduction
The researchers noted that, unlike previous reports for mepolizumab, in which low ICS adherence was linked to diminished clinical benefit, the broader anti-T2 mechanism of tezepelumab may suppress a broader range of inflammatory pathways.
They further suggested that this could enable some patients to safely reduce or even stop using ICS without worsening asthma control, while emphasising that the findings are based on 12 months of data and may not forecast longer-term outcomes.
Study limitations included the retrospective design and smaller subgroup sizes among patients with suboptimal or poor adherence, which may reduce confidence in between-group comparisons. The researchers further cautioned that the MPR may overestimate true inhaler use and recommended that future research incorporate digital inhaler technology to more accurately measure adherence.
Overall, the findings offer early real-world support for reducing ICS exposure in patients treated with tezepelumab – an important consideration given the recognised adverse effects of prolonged high-dose ICS therapy.
A prospective phase 3b clinical trial – the ARRIVAL study – is now underway to formally test whether ICS/LABA can be safely stepped down in this patient population.
Reference
D’Ancona G et al. Adherence to inhaled corticosteroids and clinical outcomes following a year of tezepelumab therapy for severe asthma. JACI In Practice 2025; S2213-2198(25)01025-6.
